Science
Related: About this forumThe First Ever Photo Showing Light as Both a Particle and a Wave
Energy-space photography of light confined on a nanowire, simultaneously showing both spatial interference and energy quantization.
The image provided is shown above, issued with the following caption from EPFL: Energy-space photography of light confined on a nanowire, simultaneously showing both spatial interference and energy quantization. If you find it all a little hard to unpack believe me, Im entirely sympathetic the team has also released this rather friendly companion video:
http://news.discovery.com/tech/photo-first-lights-captured-as-both-particle-and-wave-150302.htm
niyad
(113,628 posts)packman
(16,296 posts)surfing on waves crossed my mind. Experiment must have been done in California. Hang 10, Big Kahuna - ride those waves.
gregcrawford
(2,382 posts)That's what my acid trips used to look like! Look, Mom! I'm a wave-icle!
"Crazy Jimmy" Inhofe says quantum mechanics is a liberal hoax, so if the Sun shines equally on everyone, it must be a socialist, right?
TNNurse
(6,929 posts)But not really smart enough to understand it.
TNNurse
(6,929 posts)For those who might be interested: "Light can be both wave and particle". I like her books and I liked this one... it is remember a novel.
burrowowl
(17,653 posts)FiveGoodMen
(20,018 posts)Particularly, I'd like to know more about how to interpret the image at the top of the post.
caraher
(6,279 posts)You see in the image, along a line of a given color, a pattern of four bumps. Those bumps correspond to the locations of peaks in the standing wave of light the researchers excited along the nanowire. This is what they are referring to as the wavelike aspect of light in their data - this consistent wave structure.
Along the perpendicular direction you see two things. Imagine taking a slice through that, such that on the left you have the low peaks (in red) and on the right tall peaks. That axis represents the exchange of energy between the standing wave and the electrons used to probe the standing wave. The heights of the peaks represent something like the number of electrons that absorbed a given amount of energy from the standing wave. You'll immediately notice that only certain values of the energy absorbed by the electrons are likely - there are "valleys" between the peaks - and those peaks are roughly equal distances apart. That is the "particle nature" they are referring to - each successive peak, as one moves "out" to the left, represents electrons that absorbed 1, 2, 3, 4... photons, respectively. I think I count basically 8 peaks; I think the paper said they observed individual electrons that had absorbed as many as 9 photons (and I might not be locating "0 photons" correctly).
Peace Patriot
(24,010 posts)nt
samsingh
(17,602 posts)caraher
(6,279 posts)Someone knows how to play the PR game, that's for sure. It stretches the definition of "photo" to call this kind of reconstruction a photograph, and by what standard this qualifies as a "first ever" is completely unclear to me. I read quickly through the journal article and it appears mainly to be the first time anyone has probed certain features of a certain kind of light field with electrons this way. But I'd be awfully surprised if a little digging wouldn't turn up lots of experiments that could be plugged as "capturing light as both a particle and a wave" in a visually interesting way.
Springslips
(533 posts)In my so little knowledge of QM this article is loads of bull. ( not the science which may be good, but the journalism.) It is not decided that light is both particle and wave, other than that there is a probability wave that sometimes collapses into a particle when we measure it. Which brings up deep mysterious questions, but not the one the media likes to act like it is.
I am sure the science of this article is fascinating, but the journalism is terrible.
caraher
(6,279 posts)There's really no particular reason to expect that our minds are truly equipped to grasp in an intuitive way what happens in these systems. We have a mental model of particles, and we have a mental model of waves, and we can shoehorn observations of quantum phenomena, with varying levels of success, into these models.
Bohr tended to reframe, for excellent reasons, these discussions away from statements about what a photon (or electron or any other quantum "particle/wave" "really is" and toward what a given experiment can tell you. Experiments designed to study particle-like behaviors give particle-like results; experiments that probe wave features give wave-like results. If you take the famous 2-slit experiment and record which slit a particle passes through, the result is particle-like behavior; on the other hand, absent that information, you get wave-like results. If you do something in-between, where you have partial but not perfect information about which slit a particle may have passed through, you get something in between the particle and wave predictions. Are we observing properties of what's "out there" in nature? Or is it that, in using our experiments to understand better the microscopic world, we necessarily only look at "slices" of the phenomena that we know how to process mentally?
In this experiment, you see a standing wave pattern, which happens in physical space, as a wave-like behavior. You also see energy come out of the light field in discrete "chunks" of energy, which can be explained by absorption of individual photons. Their data looks a lot like data other graduate students in my lab ~15 years ago obtained while studying high harmonic generation, whereby an intense laser pulse interacts with an atom to create light at a much higher frequency (but always in some integer multiple of the frequency of the laser's light).